1. Field of the Invention
The present invention relates to an image recording apparatus for recording an image on a record medium being unwound from a roll.
2. Description of Related Art
As an image recording apparatus, an inkjet printer is known that has inkjet heads in each of which a large number of nozzles are formed. In the inkjet printer, ink is ejected from the nozzles of each head onto a record medium being conveyed, to record a desired image on the record medium. As the record medium for the inkjet printer, a cut sheet of paper cut in advance into a predetermined length is generally used. However, attendant upon the extension of the range of use of printers, not only such cut sheets of paper but also long papers are used for printers.
In general, a long paper is wound into a roll, which is rotatably supported by a roll supporter in a printer, for example, as disclosed in JP-A-10-139239. A portion near the leading edge of the paper being unwound from the roll is pinched by a pair of pickup rollers. In this state, the rollers are rotated. Thereby, the paper being unwound from the roll is conveyed for heads. Hereinafter, the direction in which the paper being unwound from the roll is advanced will be referred to as forward, and the reverse direction will be referred to as backward.
The paper is put on a conveyor belt of a conveyor unit and conveyed by the conveyor belt. An image is recorded on the paper at the position opposite to the nozzles of the heads. Thereafter, the paper is cut by a cutter. The part of the paper being ahead of the cutting position by the cutter is thereby cut off into a separate cut sheet discontinuous from the roll, and thereafter discharged out of the printer. On the other hand, the part of the paper in the rear of the cutting position by the cutter, on which part no image has been recorded, can be used for image recording in the next printing operation. Therefore, the part of the paper is conveyed backward to be rewound onto the roll.
The paper being unwound from the roll is apt to curve due to its tendency to curl as an aftereffect of winding. In particular, the vicinity of the leading edge of the paper is apt to greatly curve because the leading edge is an unrestrained free end.
In an inkjet printer having a construction in which a paper is put on a conveyor belt to convey, the paper being conveyed can be in close contact with the conveyor belt by the adhesion of the conveyor belt or the like so that the paper can not separate from the conveyor belt. However, the vicinity of the leading edge of the paper immediately after being cut by a cutter, is at the position of the cutter, distant forward from the conveyor belt, where the vicinity of the leading edge of the paper has been peeled off the conveyor belt. Thus, the vicinity of the leading edge of the paper is apt to curve upward due to its tendency to curl. Under this condition, if the paper is rewound as described above, the curved portion of the paper may come into contact with a head and as a result, ink may adhere to the paper.